"The news of this senseless act of violence in Las Vegas overnight is heartbreaking. Cecilia and I are beyond saddened by the tremendous loss of life. Texas mourns and prays for the victims of this tragedy, and the entire Las Vegas Community, in this time of unimaginable pain," Gov. Abbott said in a statement.

Texas senator John Cornyn has also said he's praying for victims and their families.

Senator Ted Cruz called the shooting "despicable" and offered his prayers to the victims and their families, as well as first responders.

According to early reports, Paddock had carried more than 10 rifles into a room on the 32nd floor of the Mandalay Bay Resort and Casino. He opened fire on the crowd gathered in the streets for the Route 91 Harvest festival. The shooting occurred as the event's headliner, country music artist Jason Aldean, took the stage.